Treatment of fruit and vegetable juices



Aug. 12, 1947. H. s. SCHWARZ 2,425,589

TREATIBNT OP FRUIT AND VEGETABLE JUICES Original Filed m. 16, 194043100134110 1 Henry 61 5th war Aug. 12, 1947. g, SCHWARZ 2,425,689

TREATMENT OF- FRUIT AND VEGETABLE JUICBS 'Qrigina]; Filed m. 16, 1940 4She6s-$heet 2 INVENTOR Henry 6. fchwarj ATTORNEY Aug. 12, 1947. SCHWARZTREATMENT OF FRUIT AND VEGETABLE JUICES Original Filed Feb. 16, 1940 4Sheets-Sheet 4 INVENTOR Henry 6: 5c war BY ATTORNEY Patented Aug. 12,1947 UNITED STATES PATENT OFFICE Henry G. Schwarz, Denver, Colo.,assignor to The Schwarz Engineering Company, Inc., San Francisco, CaliL,a corporation of Nevada Original application February 16, 1940, SerialNo. 319,292. Divided and this application June 9, 1943, Serial No.490,393

This invention relates to liquid treating method of a character adaptedfor homogenizing, blendlng, dispersing, and filtering operations. Ingeneral the method is adapted for use where the finely divided solidcontents or heavier liquid constituents of liquid material can betreated to remain in suspension, to be placed in solution or be filteredtherefrom to a desired extent. More particularly the-invention isconcerned with an improved method of the character referred to whereinthe liquid material to be treated is subjected to a centrifugalscreening effect.

The instant invention has for its general object the provision ofimproved liquid treating methods adapted to condition liquids withreference to the finely divided solids or heavier liquid constituentscontained therein.

This application is a division of my co-pending application Serial No.319,292, filed February 16, 1940, for Liquid treating apparatus andmethod, now Patent No. 2,340,990, issued February 8, 1944, and in whichpatent an apparatus for carrying out the method is claimed.

Other objects and advantages will be apparent from the followingdescription of an apparatus capable of carrying out the method of myinvention. i

In the drawings: a

Figure 1 is a plan view of. the apparatus with the motor and the motorsupport omitted.

Figure 2 is a side elevational view of the apparatus shown in Figure '1with certain parts indicated schematically Figure 3 is a verticalsectional elevation taken in a plane indicated by the line 3-'-3 inFigure 1.

Figure 3A is a detail view.

Figure 4 is a detailed enlarged view of one of the liquid controllingand directing surfaces of the treating chamber.

Figure 5 is a fragmentary sectional view taken ,at rightangles to theplane of Figure 3 as indicated by the line 5-5 in Figure 1. The shaftand bearing cage are shown in elevation.

Figure 6 is a horizontal sectional view with certain parts broken awaytoillustrate details of construction, the view being indicated by the line8 Claims. (Cl. 99-405) charge means from the chamber and the outletthereof by centrifugal force. For the latter purpose a rotor B isprovided which serves to feed the material outwardly against the screen,to carry the material around against the screen, and to keep suchmaterial in a turbulent condition during the time it is being fed to andforced through the screen.

Referring to Figures 1, 2, and 3, the apparatus includes a frame casting[0 which may be mounted upon a base or stand I I by means of fasteningstuds l2. The casting I0 is generally circular in form and includes abase portion 13 in the form of a ring and an upper ring portion 14 whichis supported in spaced relation from the lower ring l3 by means of aplurality of uprights l5.

As seen in Figures 3 and 5, the lower ring t3 of the frame casting hasmounted thereon a supporting spider 2| for an upright drive shaft 22,which has its lower end Journalled in thrust bearing 23. Bearing 23 ismounted in bearing cage 24 and held therein by retainer ring 28, whichalso provides a mounting for seal 21. Bearing cage 24 has threadedconnection at 28 within central boss 28 of spider 2| to provide anadjustment for the bearing 23, and may be held in a selected adjustedposition by means of a lock ring 3| suitably connected to boss 29 as bystuds 32. Adjacent its upper end, shaft 22 is journaled by bearing 30 inan upright boss 33 of a cover 34 secured by studs 36 on top ring l4 ofthe frame casting with flange 31 of a ring 38 interposed. Ring 33 isprovided with an internal frusto-conical surface 39 having liquidimpelling and directing means in the form of spaced grooves 40 (Figs. 3and 4) formed therein as referred to hereinafter.

Between the ring portions l3 and ll of the frame casting, a screen 42 ismounted in a screen frame, and preferably, the screen and the screen Isupport the screen 42. The spacing of horizontal ribs 48 providesannular discharge slots for liquid materials passing through the screen.The edges of the screen are received in machined grooves in the opposedfaces of upper and lower ri g portions 44 and 4B, the screen being slidshaft 22.

endwise into the grooves during assembly. As seen in Figure 5. the lowerring portion 48 of the screen frame has a depending flange 4| engaging acomplemental seat in ring ll (Figs. 8 and 5) which may be suitablysecured as by studs. 52 to lower ring portion I 8 of the frame casting.

Each frame section 48 of the screen assembly is held in place by asemi-circular outlet conduit 53, the two housings 53 being similar andhaving abutting end flanges 54 secured together as by bolts 55 (Fig. 7).As seen in Figs. 3, 5, and '7, each outlet conduit is provided with aninwardly projecting flange 58 at its upper end overlapping top ringportion 44 of the screen frame, while the lower wall of the conduit 88(Fig. 5) rests on lower ring part ii of the frame and has its edge inflush abutting relation to lower ring 46 of the screen frame. When thetwo conduits 53 are bolted together about the screen frame sections 48,the screen frame sections are held securely in place.

The ring 5| (Figs. 8, 5, and 6) is threaded as at 51 to receive a throatring 58 having peripheral gear teeth 58 on a lower flange thereof forengagement with an adjusting gear wheel 60 secured on a shaft 8!journaled in spaced bosses 82 of the frame casting and having a handle88 at its upper end. The gear 50 (Fig. 6) is also provided with a seriesof apertures for engagement by a locking pin .84 carried by upper boss52 (Fig. 3). The function of the adjustment of the throat member 58 willbe referred to hereinafter. To close the bottom of the chamber A, plate85 is provided, having sealed engagement at 81 with the shaft 22 (Fig.3) and releasably secured to throat ring 58 as by stud and washer means88. At its outer edge plate 58 has a raised face 88 provided with acentral annular groove I8. Face 88 of ring 85 is placed in flush sealingengagement with the bottom face of rotor B by vertical adiustmentofthroat ring 58.

The centrifugal feeding rotor B is provided in the form of a disc 16suitably secured on a flange 11; of shaft 22 and having its outer edgereduced to receive upper and lower retaining rings I8 and 18 securedthereon by bolts 80. The retaining rings 18 and 18 serve to clamp aplurality of impellers II and 82 about the periphery of the rotor B. Forthis purpose, the rings 18 and I8 have opposed flanges 88 to engage overend flanges 84 of the impellers. Impellers 8i and 82 are also secured todisc 18 and located with respect thereto by countersunk studs 85.Impellers 8i have straight sides, while the impellers 82 which in theembodiment shown comprise two diametrically opposed similar paddles havetheir leading edges slightly inclined, say about as shown in Fig. 3A. tothe vertical to force material downwardly.-

cated schematically in Fig. 5. One or both of feed pipes 80 may beemployed to feed the liquid material into the treating chamber, or, ifdesired, one of pipes 88 may be employed to introduce a treating-medium. In accordance with my method, an inert gas suchas nitrogen maybe introduced to exclude oxygen from the treating chamber. Because ofthe substantially flat upper surface of rotor B and the constrictedspace between the rotor and ring 88, a liquid seal is formed which willmaintain a gaseous agent such as nitrogen in the upper portion of thechamber without loss through the screens.

To throw material outwardly of the chamber A above the rotor B, saidrotor may be equipped with a series of angularly disposed impellers 8|(Figs. 3 and 7) whose outer edges trail slightly with respect to aradial line so that material impinging thereagainst will be thrownoutwardly toward conical surface 88 of the ring 88. As seen in Figures 3and 7, impellers 8| have their outer ends spaced closely with referenceto surface 88 and have a compiemental taper. Grooves 48 of conical wall88 are formed with an inclined side wall 82 over which liquid isreceived and a straight wall 88 forming a tooth against which the liquidimpinges to be directed downwardly and outwardly in accordance with theconical slant of surface 88. Closely adjacent the beveled lower edge ofsurface 88 upper clamping ring 18 of rotor B is provided with an opposedconical surface 84 having grooves 85 formed therein. Grooves 85 havetheir trailing edges formed substantially vertically to act as teeth orimpellers, and also angularly with respect to a radius line with theirouter edges in trailing position. The tooth-like construction of grooves40 and 85 in theclosely spaced apart surfaces 38 and 84 may be utilizedalso for a comminutlng action, if desired, and this action may becontrolled by the vertical positioning of rotor B as adjusted by gearingcage 24.

From the above description it is seen that mate rial introduced intochamber A will be thrown outwardly by the impellers 8| on the topsurface of the rotor B against theconical wall surface 38 to be directeddownwardly and outwardly through the narrow annular passage aflordedbetween the conical surface 84 at the outer edge of upper To provide adrive for the apparatus a suitable motor support 88 (Fig. 2) may besecured on top of the frame casting to support a motor (not shown)having a coupling for engagement with the drive coupling 81 at the upperend of drive I The motor employed should be capable of rotating theshaft at a high rate of speed in a counter-clockwise direction, asviewed in Figures 6 and 7, say in the neighborhood of 3600 R. P. M.Drive coupling 81 may be secured in place by fastening nut 88 having aright-hand threaded engagement with shaft 22 so that thecounterclockwise rotation tends to tighten the nut in the shaft.

To feed material into the chamber A the cover 34 may be provided with apair of feed openings 88 on which feed pipes 80 may be secured @5millretaining ring 18 of the rotor and the beveled edge of the conicalsurface 38 opposed thereto. The liquid is then forced downwardly betweenthe rotor B and the screen 42 into the annular space or chamber sectionindicated at 88 which is completely filled with the liquid.

An important feature of my method is that the liquid is carried aroundby the rotor B and its impellers 8i and 82 so that it is forced againstthe screen 42 by centrifugal force as well as by the pressure of theadditional liquid in the upper portion of the chamber A which is tryingto force its way downwardly between the rotor and the screen. To assistin the rotation of the liquid the lower retaining ring 18 of the rotoris also provided with spaced grooves 81 which provide additionalimpelling means and are opposed to a smooth conical surface 88 of thelower ring portion 48 of the screen frame, providing a narrow annularpassage which is directed downwardly and outwardly and then reverselyover the conical surface 88 at the upper end of the throat ring 58. Thelower end of the chamber, therefore, is closed by the sealing engagementof the raised face 88 with the lower face of the rotor. The grove 10 insuch face tends to collect material than the spacing between the upperopposed surfaces II and I4.

When the liquid material is introduced into the chamber A it is thrownoutwardly and whirled rapidly by the rotor B to pass downwardly throughthe narrow restriction at 39, 94 into the annular treating portion 86 ofthe treating chamber. Within the treating chamber, the liquid is carriedabout the screen rapidly by the impelling blades 8| and 82 to beimpelled against the screen by centrifugal force. A layer of solidconstituents of the material tends to build up upon the screen 42 toform a filter bed and the thickness of this layer is controlled by thelateral spacing provided between the impeller blades 8|, 82 and thescreen 42. By controlling the restriction of the discharge throat byadjustment of the throat ring 58, the rate of discharge of the heavierpulp constituents-can be controlled. In this way the heavier solidconstituents can be worked downwardly and outwardly past the throat ring58 while the juice and the lighter solid constituents are forcedoutwardly through the screen 42 for discharge. The adjustment of thethroat opening at the bottom of the annular chamber portion 98determines the proportion of the discarded solids to the solids forcedthrough the screen with the juice. The solid particles forced throughthe screen are of a size so that a large proportion will remain insuspension in the juice, so that a stable product is produced.

The filtering portion of the above described operation can be employedwith certain types of liquid material to perform a complete filteringoperation by opening the throat ring to discharge the desired amount ofsolid material and providing apertures of the proper size to excludematerial which is not desired in the filtered liquid.

In treating many products it is desirable to exclude air so that, ifdesired, one of the inlet pipes 90 can be used for introduction'of aninert gas such as nitrogen, the juice itself being introduced throughthe other of the intake pipes 90. The juiceis introduced in sufllcientvolume to be distributed throughout the upper portion of the chamber Ato form a liquid seal at the restricted space between the opposedsurfaces it and 94. In this way escape of the inert gas downwardly andoutwardly through the screen is precluded. Also, such liquid sealprevents access of air to the liquid being treated, even if an inert gasis not employed, thus minimizing oxi- -the liquid to a screening effectwhile the liquid forced out through the screen to perform an emeientmixing or blending action.

I claim:

1. In a method of treating liquid materials of the class consisting offruit and vegetable juices, which comprises continually feeding liquidsto be treated to a confined space, subjecting theliquid during feedingthereof to a centrifugal force effect to cause a whirling movementthereof, restricting the flow of liquid into the space to form a liquidseal at the entrance portion of said space. introducing an inert gasinto the space above said liquid seal to exclude the presence of oxygen,subjecting the liquid in said space to a centrifugal force effect, andfinally subjecting is still influenced by the centrifugal force.

2. In a method of treating liquid materials of the class consisting offruit and vegetable juices, which comprises continually feeding liquidsto be treated to a confined space while excluding the centrifugal forceeffect, and finally subjecting the liquid to a screening efl'ect whilethe liquid is still influenced by the centrifugal force.

3. In a method of homogenizing liquid materials of the class consistingof fruit and vegetable juices which comprises continuously feedingliquids to be treated to a confined space. subjecting the liquid duringfeeding thereof to a centrifugal force to cause flow thereof into saidspace, restricting the flow of liquid into said space to cause andmaintain a build-up of liqaid at the entrance portion thereof,subjecting the liquid in said space to a centrifugal force greater thansaid first force, and applyinga screening effect to the liquid whilesubjected to said greater centrifugal force.

4. In a method of treating liquid materials of the class consisting offruit and vegetable juices, which comprises feeding the liquid materialto be treated to a confined space while excluding the presence of air,restricting the flow of liquid at the entrance portion of said space toform a liquid seal at said entrance portion while simuldation of thematerial which might otherwise prove harmful.

Also, one feed pipe 80 may be provided with a vent valve so that thechamber can be completely filled with the liquid material to drive outthe air through the valve, which may then be closed. Subsequently,during operation the feeding of liquid material may be controlled toprevent the entry of airwith the liquid material.

In some instances it may be desirable to break up lumps or largerparticles in which event the teeth of the opposed surfaces 39 and 84 maybe employed to break up or masticate the larger particles so that theywill be in a proper condition for treatment by the centrifugal screeningeffect.

For dispersing operations, for example in dissolving or dispersingground pectin in water, or for blending liquids, the variousconstituents may be introduced into the rotor with the bottom plate 88in position to close the bottom of the treating chamber so that all ofthe material will be taneously subjecting the liquid to a centrifugalforce' effect to cooperate in maintaining such liquid seal at saidentrance portion, subjecting the liquid in said space to a centrifugalforce effect, and finally subjecting the liquid to a screening efiectwhile the liquid is still influenced by the centrifugal force.

5. In a method of treating liquid materials of the class consisting offruit and vegetable juices, which comprises feeding the material into aconfined space for treatment, subjecting the material to centrifugalforce'while the material is in said space, subjecting the liquidmaterial to a screening effect while under the influence of centrifugalforce, and subjecting the liquid material to a centrifugal force effectduring feeding thereof to said treatment space to cause it to build upat the top of said treatment space to exclude air from the materialunder treatment in said space and provide a liquid seal.

6. In a method of treating liquid materials of the class consisting offruit and vegetable juices, which comprises feeding the materialdownwardly into a confined space for treatment, subjecting the materialto centrifugal force while the material is in said space, subjecting theliqwhich will act as a seal during the relative rotation between therotor and the face 69.

The screen 42 as shown has its apertures somewhat exaggerated to moreclearly bring out its construction. In practice the size of theapertures are selected in accordance with the characteristics of thematerial to be treated. The material of the screen may be of anysuitable noncorrosive material such as stainless steel or acid resistantrubber as may be required for the different operations to be performed.

The apparatus is shown as conditioned for homogenizing, blending ordispersing operations wherein it is desirable to force all of theconstituents of the liquid through the screen to be discharged throughthe outlet conduit 63 which has discharge opening ll in communicationwith a suitable discharge pipe I02. If desired a vacuum may be appliedto pipe I02 to aid in the discharge of material through the screen.Preferably the outlet conduit 53 is also provided with a secondintegrally formed passage I03 which extends irom end to end thereof forthe passage of steam or some other suitable medium ,where it is desiredto control the temperature of the material being treated.

For filtering operations the bottom; closure plate 66 may be dropped byremoving stud and washer assemblies 60, so that the lower end of theannular chamber portion 96 is open, the size of the opening beingcontrolled by the spacing of the conical surface 99 of the ring 58 withrespect to the conical surface I04 on the rotor. By suitably adjustingthe ring 50 this spacing can be adjusted so that a desired amount of thesolids in the liquid being treated can be gradually fed downwardly andoutwardly from the chamber.

In this connection it will be noted that in accordance with my method, alayer of the solids to be filtered from the liquid will be built up onthe screen 42 to form a filter bed and that this is maintained at aconstant desired thickness by the wiping action of the impellers 8|, 82as they travel around the screen. The thickness of the filter bed may becontrolled by selecting the spacing between the outer edges of theimpellers 8i 02 and the screen, either by varying the radial dimensionof the impellers or the inner radius of the screen or-both. Obviously,if desired, all of the impellers may have straight faces as shown at 8|or inclined faces as at 82. If the bottom opening is constrictedsufllciently a greater proportion of solids will be forced through thescreen in a filtering operation by the continued application of pressurethereto, while if it is open substantially as shown practically all ofthe solids can be filtered out of liquids.

For homogenizing operation, the apparatus can be adjusted as shown inthe drawings with the bottom closure plate 66 in place. A screen 42 isemployed having the appropriate size of aperture for the material to betreated. In general, it may be stated that the size aperture requiredfor the liquid product must be selected in accordance with theparticular characteristics of the particular product. Generally, theliquid materials such as fruit and vegetable juices wherein the heavierconstituents are of a solid character such as pulp or protein particles,a larger size aperture may be employed than for products such as milkwhere the heavier constituents are of a liquid character. For example,in homogenizing a vegetable material such as carrot juice, a screenhaving apertures of a diameter in the order of .005 to .006 inch may beemployed.

Carrot Juice as well as other similar fruit and vegetable juices whenextracted and heated to a pasteurlzing temperature is subject to cogulation of a considerable proportion of certain of its constituents inparticles of sufilcient size to cause settling or separating out uponstanding to leave a substantially clear liquor. For the homogenizingoperation the carrot juice after heating to or above its finalcoagulation temperature is introduced into the feeding portion of thetreating chamber A above the rotor with the rotor rotating at anappropriate speed, for example in the neighborhood of 3600 R. P. M. Thejuice is picked up by the impellers 9!, is given a rotational directionof travel about the chamber, and is carried radially out over the topsurface of the rotor to impinge against the conical surface 39 and bedirected downwardly through the restricted annular space between therotor surface 94 and the casing surface 39, so that it is whirled aboutrapidly and is forced outwardly and downwardly into the annular space 88between the screen 42 and the rotor. As the coagulated particles passbetween the grinding teeth on the rotor and the casing the largercoagulated protein masses will be broken up,

In the treating space 96 the material is picked up by the impellers 8iand 82 and carried rapidly around the screen and at the same time isforced outwardly by centrifugal force against the screen 42 so as to beforced through the apertures therein,

During the rapid rotation of the liquid materials the impingement of thesolid constitutents against the impelling and directing surfaces as wellas the screen apertures tends to break up the larger particles. Inpassing through the apertures of thescreen, the particles are furtherbroken up and reduced in size so that they will remain in suspension inthe liquid. The discharged material from the screen is carried outthrough the respective openings i0l and the discharge pipes I02 to a canfilling machine or for other suitable disposition. The resulting carrotjuice has a high proportion of nutritive and flavoring constituents, andis of a consistency to keep a large proportion of the solid particles insuspension in the liquid.

It will be understood that with different materials the speed ofrotation of rotor B and the size apertures of the screen are selected inaccordance with the characteristics of the material to be homogenized,so that breaking up of the larger particles of the heavier constituentsof the liquid material occurs.

In treating the liquid materials, a combined homogenizing and filteringaction can be provided, so as to obtain a juice containing a desiredamount of pulp constituents, while the consistency of the juice is suchthat the pulp particles will remain in suspension and not settle out upostanding.

To further adjust the machine for filtering out undesired solidconstituents, where it is desired to remove a portion of the pulp andperform a filtering operation, the bottom plate 66 may be dropped downto provide a bottom opening in the treating chamber, and the throat ring58 is adjusted upwardly to provide the desired restriction between theopposed surfaces 99 and I04. The filtering operation can be controlledto remove a desired amount of pulp even where all the pulp constituentsare of a size to pass through the screen openings. The spacing betweenthese uid material to a screening effect while under the influence ofcentrifugal force, and subjecting the liquid material to a centrifugalforce effect during feeding thereof to said space to cause a head of theliquid material above the entrance to said space during the treatment sothat a liquid seal is provided which excludes air from the space wherethe material is being treated.

7. A method of treating material of the class consisting of fruit andvegetable juices which comprises subjecting the material in a confinedannular treatment space to centrifugal force, subjecting the material insaid space to a screening eifect while under the influence of saidcentrifugal force, providing a restricted entrance passage for thematerial into said space, and feeding such material to said entrancepassage while subjecting it to a centrifugal force effect to cooperatein maintaining a liquid seal of said material adjacent said entrancepassage to preclude access of air into the treatment space while thematerial is being treated.

8. A method of treating material of the class consisting of fruit andvegetable juices which comprises subjecting the material in a confinedannular treatment space to centrifugal force, subjecting the material insaid space to a screening efiect while under the influence of saidcentrifugal force, providing a restricted entrance passage for thematerial into said space, feeding such material to said entrance passagewhile subjecting it to a centrifugal force effect to cooperate inmaintaining a liquid seal of said material adjacent said entrancepassage to preclude access of air into the space while the material isbeing treated, and subjecting-the material to a*c0mminuting actionadjacent said entrance passage.

HENRY G. SCHWARZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES'PATENTS Number Name Date 1,999,789 Schmierer Apr. 30, 19352,089,043 Svensjo Aug. 3, 1937 2,240,213 Fromm Apr. 29, 1941 1,769,586Luense July 1, 1930 1,757,197 Johnson "a--. May 6, 1930 1,483,742 NicolFeb. 12, 1924 FOREIGN PATENTS Number Country Date 842,167 France 1939

